Grinding attachment.



H. J. HJORTH.

GRINDING ATTACHMENT.

APPLICATION FILED NOV.9, 191s.

Patented Feb. 4, 1919.

aw W/ RH 5 mw m Y I5 W 5 NH R I YW E HENRICK J. HJORTH, OF WOIBURN, MASSACHUSETTS.

GRINDING ATTACHMENT.

Specification of Letters Patent.

Patented Feb. 4, 1919.

Application filed November 9, 1916. Serial No. 130,368.

To all whom it may concern:

Be it known that I, HENRICK J. Hqonrn, a citizen of' the United States, residing at Woburn, in the county of Middlesex and State of Massachusetts, have invented new and useful Improvements in Grlnding Attachments, of which the following is a specification. I

The present invention relates to grind ng machinery and has for it particular ob ect to provide an accurately mounted and arranged power driven grinding spindle carrying a grinding wheeland arranged m such a manner that it may be mounted as an attachment to machines of various sorts, such for example as complete organized grinding machines, bench lathes, and other machine tools and machines. My invention resides both in the machine or instrument designed and arranged as an attachment, and also in the construction, design, and arrangement of a grinder spindle and its mountings, adapted not only to serve as an attachment to a machine tool, as has been above indicated, but also as the spindle of a grinder in in other arrangements. In the drawings which show the preferred present embodiment or form of my invention-- Figure 1 is a perspective view of the grinder attachment complete.

Fig. 2 is a longitudinal sectional View through the bearing of the grinder spindle showing the spindle partly in elevation and partly as being broken away.

Fig. 3 is a section of the central part of the bearing taken on a longitudinal plane at {right angles to that of the section shown in Fig. 4 is an elevation of the rear end of the spindle and its bearing.

Fig. 5 is a cross section of the spindle and bearing on line 5-5 of Fig. 2.

The same reference characters indicate the same, parts in all the figures.

In the drawings 6 represents a base on which are mounted brackets 7 and 8, the former having a bearing 9 in which is a countershaft carryin pulleys 10 and 11, and the other having a s eeve 12 inwhich is a grinder spindle 13. Said brackets or heads 7 and 8 are adjustable on the base and have clamping bolts 14 passing through the foot portions of said brackets into undercut longitudinal slots 15, 16 and carrying securing nuts 17. They have also provision for vertical ad ustment, the :part of each bracket which carries the bearin being a separate piece arranged adjustaby on the foot part. Pulley 10 is driven by belt 18 which derives its motion from any convenient external source of power while the pulley 11 drives a belt 19 which passes around a pulley 20 on the grinder spindle l3 and drives the latter.

The end of the spindle 13 has. a bore or deep socket 2'1 terminating in a threaded 301'- tion which receives the shank 22 of a grinding wheel or tool 23, the extreme inner end of said shank being threaded at 24. Preferably the socket 21 and the part of the shank which enters the same are complementally tapered so as to provide a secure and rigid mounting of the shank in the spindle.

The bearing for the spindle 13 is removable from the sleeve 12. When 1n place in the latter it is secured by clamping screws 25 which pass through ribs 26 on opposite sides of a longitudinal slot in the side of the sleeve and close said sleeve tightly upon the bearing. Said bearing comprises two cylindrical blocks 27 and 28 centrally bored to receive the shaft. The block 27 has an extension 29 at one end on which the adjacent end of the block 28 is screwed, and in such extension is a shoulder 30 abutting against an enlargement or collar 31 on the spindle. The other block has a web 32 adapted to bear against the opposite end or face of the enlargement 31; the shoulder 30 and web 32 forming end thrust bearings which co-act with the enlargement 31 to prevent endw'lse movement of the spindle. Looseness or end shake in the thrust bearing may be taken up by adjusting one of the blocks upon the other, the proper adjustment being securely maintained by a locking ring or nut 33 which is screwed upon the extension 29 and bears against the end of the block 28.

The spindle has a central lateral bearing in the extension 29 and in the adjacent part of the block 27. Its ends have their bearings in bushings 34 and 35 which fit closely upon the spindle and are entered into coaxial sockets 36, 37 in the blocks. Nuts 38, 39 are screwed on the outer ends of said bushings, and are set against shoulders adjacent to the ends of the blocks 27 and 28 and have lips 40 which are overlapped by the inner edges of retaining rings 41 which surround these heads and are secured to the blocks by screws 42, as clearly shown in Fig. 2. The bushings are prevented from turning by screw studs 43 removably fitted in tapped holes in the blocks and having key ribs on their inner ends entering slots 44 in these bushings. The fiat sides of said key ribs engaging the sides of the keyways prevent the studs from turning and can not accidentally become dislodged when the bushings are in place.

For lubrication there is provided an oil hole 45 entering the socket 37 through the side of the block 28, a similar hole 46 entering the socket 36 through the side of the block 27 and a third oil hole 47 through the block 27 intersecting one of several passages 48 through the extension part 29 of the block 27 running from the socket 36 to the end of said extension. Passages 48 conduct oil to the enlargement 31 and the thrust bearing shoulder 30. In the web 32 are passages 49 from the socket 37 which admit oil to the bearing surface of said web. All of the oil holes are closed by screw plugs 50 which are removable at need. Each of the sockets is enlarged between its ends, and at its extreme inner end, to provide annular chambers containing oil. Preferably the larger of the chambers in each socket contains a body of absorbent material, such as felt, to soak up and retain the oil. The bushings 34 and 35 have a number of longitudinal slots in which are contained wicks 51 to soak up oil and continuously feed it to the adjacent surface of the spindle, and in theouter portion of the key way 44 is a similar wick 52 for lubricating the end of the bearing.

A most important feature of the invention consists in the fact that the bearing bushings may be adjusted with the utmost ease to take up wear. Their outer surfaces are tapered as shown in the sectional views, and the inner walls of the sockets in the blocks are complementally tapered, except that those portions which are enlarged to form oil chambers as previously described; the extent of contact between the surfaces of the bushings and sockets being sufficient for the purpose of compressing the bushing upon the spindle. The keyway 44 in each bushing extends the entire length of the bushing so that the latter is in effect a split sleeve. Consequently, then, by forcing these externally tapered split sleeves into the sockets more or less they can be sprung so as to fit more or less closely upon the spindle, and may thus be adjusted to take up looseness as they wear. The nuts 38 and 39 serve as the means for so adjusting the bushings. Such nuts project beyond the retaining rings 41, as shown in Fig. 2, and are flattened at opposite sides as shown in Fig. 4 so that they may be turnedby a wrench. The retaining rings serve as the abutments against which the lips 40 of the nuts bear when the latter are turned to adjust thevbushings so as to take up wear. Thus any side shake of the spindle may be eliminated as soon as it occurs by simply turning one or both of the nuts 38 or 39 without dismantling the fixture, and even while the spindle is running. Particularly it is to be-noted that the adjustment of these bushings does not alter the position of the grinding wheel in the slightest.

It will be apparent that the elements hereinbefore describedconstitute a simple and accurate means for mounting a grinding tool, one which can be applied in a variety of ways according to the purposes for which it is used. An especially useful featureresides in the accuracy of the means for mounting the grinding spindle, which is the most important aspect of any grinding machine. The bearing elements or members for the spindle, by which its accurate location and running are secured, consists of the bushings 34 and 35, mounted in a rigid holder. These bushings en age the spindle near its extreme ends, there y making it as steady as possible, and are readily removable, whereby others may 'be substituted when those previously in place become worn out. The fact that the bushings are so small and easily removable makes their replacement when worn a matter of the utmost simplicity and of the most trifling expense. The end thrust bearing is another important feature, as it securely holds the spindle against displacement in either direction, and is adjustable in a simple manner to take up end shake. The position of the end thrust bearing between the lateral bearings enables the latter to be placed at the ends of the spindle; while the lateral bearings are entirely independent of the end'thrust bearing and are susceptible of adjustment without aifecting the latter.

What I claim and desire to secure by'Letters Patent is;

1. A grinding attachment comprising a base, a bracket mounted on saidbase having a sleeve portion, bearing blocks coupled together contained in said sleeve portion and a spindle rotatably mounted in said bearing blocks, the spindle having an end thrust collar and the bearing blocks being relatively adjustable and having abutments engaging opposite ends of said collar.

2. A. grinding attachment comprising a pair of alined bearingblocks one of which is screwed upon the other, a grinder spindle having lateral bearings in said blocks and having an enlargement between the blocks, and each of said blocks having an abutment or bearing surface engaging one of the ends of said enlargement.

3. The combination of a spindle, axially alined bearing blocks containing said spindle, one of'said blocks being screwed upon the other and adjustable endwise with respect thereto, bushing detachably contained in the blocks, throughwhich the spindle passes, and said blocks having adjacent face fitting the tapered surface of said shoulders and the spindle having an ensocket, a nut screwed upon the bushing and largement located between said shoulders abutting against the end of the block, a reconstituting an end thrust bearing. tainer secured to said block overlying a 85 4. A grinder spindle having an enlargeportion of said nut to retain the same in ment between its ends, a holder for said place and serve as an abutment for the nut,

spindle having end thrust bearing surfaces and means for restraining the bushing from engaging opposite end faces of said enlargerotation relatively to the block.

ment, and side bearings, each of uniform 7. The combination with a grinder spindle 40 diameter internally throughout its entire having an enlargement, blocks adjustably length, for the spindle adjacent to the ends connected together having end thrust surof the latter on each side of said enlargefaces respectively engaging opposite ends of ment. said enlargement, and lateral bearing bush- 5. The combination of a spindle, a block ings entering the outer ends of said blocks 45 in which said spindle is rotatably contained and fitting the spindle, said bushings being having a socket at one end with a tapered independent of the end thrust bearing.

internal surface, a longitudinally split bush- 8. The combination with a grinder spindle ing surrounding the spindle entering said having an enlargement, blocks adjustably socket and having an externally tapered surconnected together having end thrust surto face fitting the tapered surface of said faces respectively engaging opposite ends of socket, a nut screwed upon the bushing and said enlargement, and lateral bearing bushabutting against the end of the block, and ings entering the outer ends of said blocks a retainer secured to said block overlying and fitting the spindle, said bushings being a portion of said nut to retain the same in externally tapered and the portions of the 6B place and serve as an abutment for the nut. blocks wherein they are received being com- 6. The combination of a spindle, a block plementally tapered, and means for adjustin which said spindle is rotatably contained ing said bushings endwise to compress them having a socket at one end with a tapered toward the spindles for taking up wear.

internal surface, a longitudinally split bush- In testimony whereof I have afiixed my 60 ing surrounding the spindle entering said signature.

socket and having an externally tapered sur- HENRICK J. HJORTH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patenta. Z Washington, D. G. 

